Battery charging thermostat



May 27 1947 B. F. w. HEYER Re. 22,883

BATTERYv CHARGING THERMOSTAT OriginalvFiled Aug.17. 1942 2 Shets-Sheet 1 May 27, 1947. B. F. w. HEYER BATTERY CHRGIHG THERMOSTAT y Original Filed Aug. 17. 19,42

2 Sheets-Sheet 2 Mey 21, 1947 Ref 2215883,"

UNITED j sTATl-:s PATENT oFFlcE F. W. Beyer, Tenaiiy, N. J., assignor to John J. McDonough, trustee, Newark, N. J.

rlgiual No 2,376,056,1dated May 15, 1945, Serial No..455,113, August 17, 1942. Application ior reissue May 8,1946, Serial No. 667,512

This invention relates to thermostatically actuated switches, and more particularly has reference to a switch of this type constructed for insertion in the electrolyte of a battery while b eing charged.

In the use of so-called fast chargers for charging batteries, it is essential to prevent overheating oi the batteries due to the high current passing therethrough. Obviously, the best indication of the temperature oi' the battery being charged is the temperature oi' the electrolyte as this is in immediate contact with the plates, and the temperature thereof will correspond to the temperature of the essential elements of the battery.

It is also important that the battery be charged as much as possible up to the'temperature limit above which damage to the battery will result, without exceeding such limit. Consequently, any thermostatic control device must be' very accurate so as to obtain the maximum charge and yet avoid damage to the battery. Thermostats heretofore constructed for this purpose have not been as accurate as is desired and up until the present there has been no device available for accomplishing the exact control of the charging curreni*l relative to the battery temperature toenable the maximum charging of a battery up to Another object of this invention is to provide I a thermostatic switch for controlling the charging of batteries which isadapted to be immersed in the electrolyte oi the battery and is highly sensitive to temperature changes to enable the 18 Claims. (Cl. 177-311) ber sheath sealed to the heat conducting sheathl and to said housing. i A

' A still furtherobiect of this invention is to provide a tool for adjusting a thermostatic switch constructed in accordance with the present ingvention and equipped with means for indicating maximum charge to be introduced into the battel-y without exceeding predetermined temperature limits.

A further object oi.' this invention is to provide a thermostatically actuated switch which can be easily and accurately adjusted for operation at predetermined temperatures and will maintain such adjustment.'

Still another object of this invention is to provide a thermostatically controlled switch which comprises a housing having a thermostat mounted on oneend thereof and provided witha bulb for immersion in the electrolyte ofa battery to be charged, a switch actuated by said thermostat and enclosed within said housing, said bulb being encased in an acid resisting heat conductive when a proper adjustment has been obtained.

The present invention also has for an object a thermostatically controlled switch for use in battery charging which comprises a. housinghaving an interiorly threaded portion, a support adjustably enthreaded in said housing and carrying a, switch mechanism, a thermostat mounted in said housing and having a movable' member for actuating said switch, and means for adjustlng the position of said support axially within said housing relatively to the movable member of the thermostat.

With these and other objects in view,y the present invention resides in the parts and combinations hereinafter illustrated and described. vTo facilitate an understanding of `the present invention an embodiment thereof has been illustrated in the accompanying drawings in which: Figure 1 is a longitudinal sectional view of a thermostatic switch' constructed in accordance vwith the present invention.

Figure 2 is a sectional view taken on line 2-2 of Figure 1.

Figure 3 is a, sectional view taken on line 3-3 of Figure 1.

Figure 4 is a sectional view taken on line 4 4V v Figure '7 is a diagrammatic representation of the wrench and thermostat taken lon line 8--9 of Figure 7.

`A thermostatic switch embodying the principles of the present invention as illustrated in the drawings comprises a housing I which is in the form oi a tube of steel or other suitable material having a portion of the interior surface thereof adjacent one end provided `with screw threads 2. 'I'he other end of the tubular housing is bored out to form a shoulder 3 which serves as a seat for a thermostat to be mounted therein.

sheath and said housing being encased in a'rub- 56 It is essential to the present invention that the cases Y 3 tnexmostnt be nxediy mounted within the nousing IA d for this purpo the thermostat isprovidedV th a; portion-I having a circumferential flange/[which is adapted to be seated-J on the shoulder '3 the lowerv end1 of the tubular housing I.A VIn order to effectively retain the flange l against the shoulder 3, the lower end of the tubular housing `I is turned over as indicated by reference character 3. This construction serves torigidly mount the thermostat relative to the housing I.

rodr, the latter is provided with a bore in the end which passes-through the central opening as lnndin whion is mounted an insulating plug Extending from the lower end of the. housing Y I is the bulb 1 of the thermostat which is to be immersed in a liquid such as'the electrolyte of a battery the temperature oi?V which isjto affect the thermostat.Y Bulb 'I may be lled with turpentine or other suitable material which has an expansion coeilicient suitable, for the purpose. The upper end of the thermostat comprises a bellows 3 to the freeend of whichissecureda movable member in the form of a pusher rod' 3. Upon` expansionof the liquid within the bulb 1, the bellowsiscausedtoexpandandinturnthe movable member I is displaced axially of the housing I.

Positioned in the upper end of the housing I is a cylindrical body or disc 'Il of steel or other suitable material the circumference of y which is threaded to cooperate with the threads 2 in the housing I. Mounted on the support disc I0 is a switch in the form of a contact spring element II whichis securedtothe disc by means of studs I2 Yand I3. A disc or plate of insulating material I4 is interposed'between the body Il and the spring I I. The studs I2 and I3 are insulated 'from the disc I3 by means of sleeves I5 and It of insulating material so that there is no electrical contact vbetween the studs I2 and I3 and the disc I0. Studs I2 and I3 are provided with heads I1 and I3 of enlarged diameter from which extend the terminal posts I3 and 23. Interposedbetween the heads I1 and the disc Il is the fixed end of spring II and a pair of metal washers 2l to insure a conductive connection between spring II and the head I1. The opening in the fixed end of spring II through which the stud I3 extends is of a diameter* larger than that of the'stud and maybelledwitharingofinsulationtoinsulate the spring I I from stud I3. An insulating disc or washer 22 ilies directly von spring I I and serves to insulate spring II fromthe head I8 and any intervening metal washers.

On the under side of the body I0, washers of insu1ati'onf23 and`24 are mounted on studs I2 andj la. A nitaifwnsher z5 is positioned on'stud lz kand a' Ju'mperiirv conductor strip 23 is positioned on stud I3. Strip 28 serves to connect stud I3 to a iixed contact 21 which is rigidly and insulated-ly mounted in the disc III. The lower ends of studs I2 and I3 and contact 21 are peened to rivet the assembly securelyrtogether. This arrangement vof structurels clearly illustrated in Figure 5 of onthe side orf the/disc III remote from the theraccidentally varied.

y it will remain wherever it is set.

30 which serves to make actual contact with the spring II. v

When the threaded body I0 is in a position whereby the insulating element 30 of the pusher rod l is in engagement with the spring Il, heating of the thermostat bulb 1 will cause the liquid therein to expand and this in turn will effect a displacement of the pusher rod 9 and, will cause the spring II to be displaced to separate/the contacts 21 and 2l. By adjusting the axial position of the body Il and the spring II in the housing 2 relative to the end of the pusher rod,- the separation of the contacts 21 and 23 will take place at various predetermined temperatures. To

return the bellows to its normal position uponv y since the thermostauonuy actuated switch in' accordance with the present invention will be subjected to mechanical shocks in use, the position of the body I0 within the housing may be To overcome this, the present invention provides means carried by the body III for frictionally engaging the threads 2 and vthereby frictionally locking the body I0 1n ali-v justed positions within the housing I. The frictional means found to be particularly suitable is,y as shown in' the several figures of the drawings, in the form of the fiber plate or washer Il.

This plate is made to project beyond the peripheral edge of body III and is larger than the internal threaded portion of the housing I, so that when the body III is screwed into the housing I, partial threads will be pressed into the projected portions of the plate I4. This puts a heavy drag or friction on the turning of the body lil so that No amount of use or vibration will cause the body Il) to be accidentally rotated within the housing. This friction lock enables the body III to be more easily adjusted in a manner which is quicker land easier than if set screws were used to hold the body in adjusted position y In actual use, the plate I I is made in the form of a disc with three lugs spaced substantially apart and projecting beyond the peripheral portion of the body I0. It will be noted that by providing only three lugs 32 spaced 90 apart there is no projecting lug on one side of the plate Il. 'I'he eiiect of this construction is for the' projecting lugs 32 to force the threaded body I0 on the side where there are no lugs 32 against the threads within the housing I and be frictionally retained in the adjusted position.

Although three lugs 32 positioned 90 apart are eiIective, it is not indispensable to the present invention as a locking action will be provided g regardless ofthe number of lugs, and as a matter of fact even when the engagement between the edge of plate I4 and the threads of the housing I is continuous throughout the circumference off the plate.

In assembling the body III within the housing I, the body is screwed into the same by means of wrench 33 which is provided with sockets to receive the upper portions of the studs I2 and I3.

i As illustrated in Figure 8 of the drawings the wrench 33 comprises an insulated body member having tubes 34 and 35 positioned therein to receive 'the upper parts I3 and 2D of the studs I2 and I3. The lower ends of the tubes 34 and 35 are enlarged to form sockets to receive the heads I'I andlofthestuds I2 and I3.

The `tubes 34 and 35 are constructed of metal and are connected to conductors 3G and 3'I which form part of a test circuit including a battery 3B and a lamp 39. In the form of switch illustrated in the drawings, the contacts 2'I and 23 are normally engaged and are adapted to be opened when the temperature of the electrolyte is suflicient to cause the thermostat to operate. Thus, the test circuit including the battery 38 and 39 will be completed through the tubes 34 and 35 and the contacts 21 and 28 of the switch. In adjusting the position of body III, the bulb 'I is immersed in the test bath 4B which is at the temperature at which the switch is to open and body IB is moved into the housing I until the light 39 is extinguished by reason of the element 3i!v engaging the spring II and causing the contacts 21 and 28 to be separated.

After the body I Il is adjusted to the proper position within the housing I to cause the switch to operate at the desired temperature, conductors 4I which are part of .the charging circuit are soldered to the terminals I9 and 20 on the upper ends of the studs I2 and I3 and the cable containing the conductors 4I is passed through a strain relief 42 which is mounted in an opening within a closure 43 which is secured in place on the upper end of the housing I. The closure 43 may be soldered or otherwise secured to the housing I to maintain a. tightly closed container.

Since the thermostatic switch in accordance with the present invention is to be used by insertion within the iller opening of a battery, the bulb I must be encased in a sheath 44 of material which has both heat conducting and acid resisting properties. For this purpose, it is found that the sheath 44 may be constructed of an alloy oontaining approximately 6% antimony and the balance lead.

To protect the other parts of the thermostat including the housing I, a sheath 45 of rubber is snugly tted over the entire housing I and the closure element 43. The lower end of the rubber sheath 45 extends down over a portion of the lead sheath 4'4 which encases the bulb 1. The rubber sheath 45 is formed of a size so that it will snugly ilt the housing I and associated parts and is stretched over the housing by means of a special tool which is not part of the present invention. Before the rubber sheath is entirely collapsed to snugly grip the thermostat, an acidproof rubber cement is forced between the sheath and the thermostat so that at the juncture oi the cable 4I, strain relief 42, and closure 43, a seal 46 6 is provided. Also,4 at the junctin'e of the lower end of the housing I and the lead sheath 44, another seal 41 is provided. These seals are so formed as to prevent any acid reaching the metal parts of the thermostat and its housing.

` A rubber baille 4l is molmted over the lower end of the rubber sheath and is retained in place by a bead 43. This baille will prevent excessive spraying of acid from the filler opening in which the thermostat bulb 1 is inserted during charging of the battery.

Instead of rubber, other suitable plastic material having acid resisting properties may be used.

From the foregoing description it will be appreciated 4that the present invention provides a thermostat construction which avoids the prior art disadvantages and which is easily made and adjusted. Y

I claim:

1. A control switch comprising a housing element having a bore therein the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedly mounted in said bore, a switch assembly having a movable member and carried by said threaded support element,I an actuating member carried by said housing for actuating the movable member of said switch assembly, said threaded support element being rotatably adjustable in said threaded bore for axial displacement relative to said actuating member', and means carried by one element and frictionally engaging theA threaded surface of the other to frictionally restrain said elements against relative movement. l

2. A control switch comprising a housing having a threaded bore therein, a threaded support threadedly mounted insaid bore, a switch assembly having a movable element and carried by said threaded support, an actuating element carried bysaid housing for actuating 'the movable element of said switch assembly, said threaded support being rotatably adjustable in said threaded bore for axial displacement relative to said actuating elemmt, and means carried by said support for frictiorally engaging the threaded surface of the bore to retain the support in adjusted positions.

3. A control switch comprising a housing having a threaded bore therein, a threaded support threadedly mounted/"in said bore, a. switch assembly having a movable element and carried by said threaded support, an actuating element extending into said bore for actuating the movable l 4. A control switch comprising a housing having a threaded bore therein, a threaded support threadedly mounted in said bore, a switch assembly having a movable element and carried by said threaded support, an actuating element extending into said bore for actuating the movable element of said switch assembly, said thread- Ved support being rotatably adjustable in said threaded bore for axial displacement relative to said actuating element, and a plate of friction material carried by said support and having portions projecting beyond the threaded surface of eases A ed bore for exie1 displacement remove y'to seid actuating member, and lugs of friction producsembly having a movable element and carried by' said threaded supporta thermostat carried by said housing and having a temperature responsive displaced member for actuating the movable element of the switch, said threaded support being rotatably adjustable in said threaded bore for axial displacement relative to said actuating member, and means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elements against relative movement. Y

Y 6. A thermostatic switch for use in battery charging comprising a tubular housing element, a-thermostat having a body portion mounted in the housing and an extension projecting beyond the end of the housing for insertion in the electrolyte of a battery to be charged, a movable actuating member on saidthermostat extending into said tubular housing, the inner surface of said housing element being threaded, a support element having a threaded external cylindrical surface threadedly mounted in the threaded portion of said housing element, a switch assembly having a vmovable member and carried by said threaded support element, said' threaded support element being rotatably adjustable in saidlthreaded bore for axial displacement ofthe latter relative to said actuating member, and means carried by one element and frictionally engaging' ing material carried by and projecting beyond the threaded surface of the support rfor frictionally engaging the threaded inner surface oi the housing element to retain the support in adjusted positions.

9. A thermostatic switch for use in battery charging comprising .a tubular housing element..

a thermostat having a body portion mounted in the housingand a bulb projecting beyond the end of the housing for insertion in the electrolyte of a battery to be charged, a movable actuating member on said thermostat extending into .said tubular housing, the inner surface of said housing element being threaded, a support element having a threaded external cylindrical surface threadedly mounted in the threaded portion of said housing element, a switch assembly having a movable member and carried by` said threaded support element, said threaded support element being rotatably adjustable in said threadthe threaded surface of the other to frictionally restrain said elements against relative movement. y

7. A thermostatic switch for use in battery charging comprising a tubular housing element, a thermostat having a body portion mounted in the housing and an extension'- projecting beyond the end of the housing for insertion inthe electrolyte of a battery to be charged, la. movable actuating member on said thermostat extending into said tubular housing, the inner surface ois element being rotatably adjustableinsaid threaded bore for axial displacement relative to said 'actuating member, and means carried by said support element for frictionally engaging the threaded surface of the housing element to retain the support in adjusted positions.

8.- A thermostatic switch for use in battery charging comprising 'a tubular housing element,

ed bore for axial displacement relative to said the support for frictionally engaging the threaded inner surface of the housing to frictionally retain the support in adjusted positions.

10. An apparatus for adjusting a control switch having a housing element provided with a bore therein the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedly mounted in said bore, a switch assembly having xed and movable contact members and a port element being rotatably adjustable in said threaded bore for axial displacement relative to said actuating member, means carried byone element and frictionally engaging the threaded surface of the other to frictionally restrain said elements against relative movement, said apparatus comprising a tool having insulated contacts for engaging the terminals on said support elementfor adjusting the position ni thelatter, and means for indicating whether the contact members are :losed or separated.

11. An apparatus for adjusting a control switch having a housing element providcd with a bore therein the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedly mounted in .said bore, a switch assembly having fixed and movable contact members and a terminal for each contact member carried by said a thermostat having a body portion mounted in I the housing and an extension projecting beyondv the end of the housing for insertion in the electrolyte of a battery to'be charged, a movable actuating member on said thermostat extending surface threadedly mounted in the threaded portion of said housing element, a switch assembly having a movable member and carried by said threaded support element, said threaded support element being rotatably adjustable in said threadsupport element, an actuating member carried by said housing for aztuating the movable mem- 'ber of said switch assembly, said threaded support element being rotatably adjustable in said threaded bore for axial displacement relative t0 said actuating member, means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elelated contacts .and adaptedY to` be completed byV the closure of said contact members.

eases 12. An apparatus for adjusting a control switch having a housing element provided with a bore therein the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedly `mounted in said bore, a switch assembly having i'lxed and movable contact members and a terminal for each contact member carried by said supportI element, an actuating member carried by said housing for actuating the movable member of said switch assembly, said threaded support element being rotatably adjustable in said threaded bore for axial displacement of the latter relative to said actuating member, means carried by one element and frictionally engaging the threaded surface of the other to frictionally restrain said elements against relative movement, said apparatus-comprising a tool having insulated contact sockets for receiving the terminals on said ,supportl for adjusting the position of the latter, and means for indicating whether the contact members are closed or separated.

13.- A temperature controlling device for use in battery chargers. said device comprising a housing open at both ends, a thermostatic member having a body portion secured in one of said open ends, a bulb containing an expansible iluid formed on one side of said member and extending beyond said housing for insertion into the electrolyte of a battery under charge, a switch unit having a xed and movable contact disposed in the other end of said housing, said contacts bcing normally closed, actuating means formed on the other side of said member and extending into said housing to a position adjacent said movable contact, said switch being movable axially in said housing for varying the position of the movable contact relative to said actuating means t thereby control the temperature at which a battery may be charged, and means carried by said switch for frictionally engaging the housing for retaining the switch in its adjusted position.

14. A control switch comprising a housing element having a bore therein. the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedly mounted in said bore, a switch assembly having a movable member and carried by said threaded support element, an actuating member carried by said housing for actuating the movable member of said switch assembly, said threaded support element being rotatably adjustable in said\t`,hreaded bore for axial movement relative to said-actuating member, and means cooperating with thethreaded surface of at least one of said elements to restrain said elements against relative movement.

15. A thermostatic switch for use in battery charging comprising a tubular housing element, a thermostat having a body portion mounted in the housing and an extension projecting beyond the end/ of the housing for insertion in the electrolyte of a battery to be charged, a movable actuating member on said thermostat extendina into said tubular housing. the inner surface of said housing element being threaded, a support element having a threaded external cylindrical surface threadedly. mounted in the threaded portion of said housing element. a switch assembly having a movable member and carried by said threaded support element, said threaded support element being rotatably adjustable in said threaded bore for axial displacement of the latter relative to said actuating member, and means cooperating with the threaded surface of at least one of said elements to restrain said elements against relative movement.

16. A control switch comprising a housing element having a bore therein, the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedly mountedin said bore, a switch assembly having a movable member and carried by said threaded support element, an actuating member carried by said housing for 4actuating the movable member of said switch assembly, said threaded support element being rotatably adlustable in said threaded bore for axial movement relative to said actuating member, and means to restrain said elements against relative movement.

17. A control switch comprising a housing element having a bore therein, the inner cylindrical surface of which is threaded, a support element having a threaded external cylindrical surface threadedlymounted in said bore, a switch assembly having a movablevmember and carried by said threaded support element, and an actuating member carried by said housing for actuating the movable member of said switch assembly, said threaded support element being rotatably adjustable in said threaded bore for axial movement relative'to said actuating member.

18. A thermostatic switch for use in battery charging comprising a tubular housing element, a thermostat having a body portion mounted in the housing and an extension projecting beyond the end of the housing for insertion in the electrolyte of a battery to be charged, a movable actuating member on said thermostat extending into said tubular housing, the inner surface of said housing element being threaded, a support element having a threaded external cylindrical surface threadedly mounted in the threaded portion'of said housing element, and a switch assembly having a movable member and carried by said threaded support element, said threaded support element being rotatably adjustable in said threaded bore for axial displacement of the latter relative to said actuating member.

BENJAMIN F. W. HEYER.

REFERENCES CITED UNITED STATES PATENTS Name Date Raney Oct. 31, 1933 Number 

